Hi all, first post here....just received my new Lumia 640 today in the mail (unlocked ATT model off ebay), and of course real excited to get using it. I've enjoyed the T-mobile 521 I've used for the last 18 months, but time to give myself a little upgrade! So, not wanting to screw anything up (I haven't even put my T-mobile sim in it yet!), what do you figure is the best plan of attack with the ultimate goal of running W10 on it? Do I try to install W10 right off the bat (i guess from the insider route so I have read?), or go with the normal progression of starting the phone and restore using a 521 backup, make sure the phone works, etc, and then wait on formal release of W10 later? Thanks- first time I have been really excited about getting a new phone!